The 4Cs of a diamond


A good cut gives a diamond optical efficiency – the way it handles light for maximum brilliance, fire and scintillation. A gemologist evaluates a diamond’s cut base on its girdle, table size, crown angle, pavilion depth, and culet size. The details of the cut are made up of Polish and Symmetry. All Cut, Polish and Symmetry should be graded under the following 5 levels. A diamond with “triple excellent” is believed to emit maximum light returns.


Diamonds that range from colorless to light yellow/light brown are graded under the D-to-Z range. A gemologist values color based on how noticeable the color is, using naked eye, by comparison against the master set stones. All other value factors being equal, colorless diamonds are the most valuable and desirable because of their rarity.


A diamond’s clarity refers to the freedom from the presence of characteristics on and within the stone. Blemishes are confined to the surface, while inclusions are typically enclosed within a diamond (or extend from the surface into the diamond). The factors that determine the effect of characteristics on a clarity grades are size, number, position, nature and relief. The grades to describe the clarity are


The carat represents the weight of a diamond. One metric carat equals to 0.2grams. Therefore a 1 carat diamond might have diameter that ranges from 6mm to 6.6mm. The magic sizes, which are popular, are probably 0.30ct, 0.50ct, 0.70ct, 1ct, 1.2ct, 1.5ct, 2ct and so on. All the 4Cs play important roles in determining the value of a diamond.